It still feels odd to type those words. 5 months ago I had never done any running. Ever. Now I have completed one of the most prestigious marathons in the world.

As I wrote in my previous post though I had a very strong motivation. Without that I don't think I would have been able to find the resolve to stick with the training and ultimately follow through on it. But knowing I was raising money for COSMIC made the difference.

I have never experienced anything like the day of the marathon itself.

The starting area in Greenwich for those of us in the Red area (the slow people) was reminiscent of a music festival with music, large screens everywhere, stalls and toilets. There was a real sense of camaraderie as we all milled about and eventually started queuing up. After the 10am start time it actually took us 26 minutes to inch forward and so eventually I crossed the starting line at 10:26am.

I was determined this time to stick to the sort of pace I thought I could actually sustain for 26.2 miles. When I had done the Taunton Half Marathon 3 weeks earlier I had gone off at a pace of 11 minute miles mistakenly thinking I could sustain that for 13.1 miles but I had been wrong and the last 5 miles of that half marathon had been hell. I had also felt ill for several days afterwards. So I chose a much slower pace for the marathon of 13.5 minute miles. And in fact I was quite happy to drift below that if it felt right.

This meant that I was running at a pace only maybe 30% faster than I could probably have walked it. But I was still running! I kept finding throughout the race that people who had gone past me earlier at a faster pace, I was then overtaking as they stopped to walk for a while. And then a few minutes later they would overtake me again. But I was happy with my steady plodding pace and I was able to sustain it for most of the race.

I did slow down to a walking pace a few times but only for 1 or 2 minutes at a time every time I came to a water station. This was at least partly to avoid tripping over the water bottles strewn over the road. There was also a point at mile 18 where there was a very steep hill and literally everyone slowed down to walking pace for about 5 minutes so I did that too.

All along the route were people. Tens of thousands of people. I heard my name shouted every few seconds thanks to the very large name badge I had pinned to my running vest (in Superman colours!) that my wife had kindly made for me. "Come on Mark!". "You can do it Mark!". "You've got this Mark!" (I heard that individual one about 50 times). There must have been well over a thousand people who I heard shouting encouragement directly at me.

What was happening en-route was akin to a 26.2 mile street party. There were DJs. Bands. People dressed up in costumes playing parts. For example at one point there was a man dressed as a paramilitary policeman with a sign that said "Run - It's the law!" shouting legal threats through a loudhailer. But there were countless other things like that all along the way.

Some of the signs were very amusing as I flashed by them trying to read them. "You think your legs are tired? My arms are killing me!", "Wave if you think this was a worse idea than Brexit", "Keep Calm and Don't Shit Yourself" complete with a cartoon picture of a turd - these were just few of the many that I saw.

People were giving out jelly babies, jelly beans, Haribo sweets, chocolate. All sorts. I had vowed not to take any of these pre-race as I had trained using a specific type of gel block that I had in my pouch. But by half way round my body was telling me it needed more than one of those tiny cubes of jelly every three miles. So I popped into a shop en-route and bought a Picnic bar which I wolfed down whilst running! That lasted me a few more miles. But my body was screaming out for more energy so I started taking jelly babies, jelly beans, kit-kats, other chocolate. Anything I could lay my hands on. I even grabbed a banana at one point. That was a good move as it really settled my metabolism down 10 minutes or so later.

My experience of the running was mixed. Sometimes it felt like hard work. Sometimes it felt like I was really in the zone and it didn't feel hard at all. And then there was another thing I experienced between about mile 14 and mile 18 which was a feeling that I was just in tune with my animal instincts. I didn't really think about anything. I had tuned everything else out. I was just running. left foot, right foot, left foot, right foot. Run. Run. Run. Run. There was nothing else but running.

I had never experienced that in any of my training. It only lasted for about an hour but it really helped me get through those few miles.

I played an interesting psychological game with myself once I got past about mile 19. My body was aching and sore. It was getting increasingly hard to keep going. But looking at my time I was around 4 and 3/4 hours. And when I got to mile 20 I knew that even if I were to completely stop running now and just walk I would almost certainly still complete the marathon within the 8 hour limit (the time within which you still get a medal and an official finishing time). But because I knew that I felt the pressure lift. I knew I was going to finish. I knew I was going to get a time. I knew I was going to have completed the London Marathon! And so every extra mile I did running beyond mile 20 was "voluntary". This really helped as I was choosing to keep running even though I didn't actually have to any more. At mile 21 I just told myself one more mile. I did the same at mile 22. It was getting very very hard. My body was screaming at me to stop running but at mile 23 I told myself just one more mile. At mile 24 my body was screaming even more loudly to stop and start walking. I kept going for a few hundred more yards. then I looked at the time. I was 5 hours and 50 minutes in. I thought about the less than 2 miles I had to go and I took a decision. If I carried on running there was a risk I might burn myself out before the end. We've all seen the footage of people whose legs turn to jelly (indeed there was an elite runner this year who did this a few hundred yards from the finish).

So I decided when I was around 1.8 miles from the finish to slow down and start walking. It felt like a relief. I was walking more slowly than I ordinarily would. My left knee was very, very sore (I had an injury that I had picked up during training). My right knee was also quite sore. My legs, neck and arms were aching. But I could walk. It was a pace of around 20 minute miles (3 miles per hour). And I was sustaining it no problem. In fact after 10 minutes or so of this I felt very good.

At this point I spotted my brother and his girlfriend in the crowd. I went over and chatted to them briefly but I needed to keep walking before I seized up. Then I saw my wife and son in the crowd just a bit further up. I went to them and held my 2 year old son Noah who had just woken up. I hugged him and my wife which was a real boost. But I had to keep going.

I got to around half a mile from the finish and I then decided the time had come to start running again. I was going to finish as I had started. I picked up the pace and before I knew it I was running round the corner into The Mall. The finish line was visible now. It got nearer and nearer. I had enough left in the tank to pick up the pace even further and I ended up overtaking a bunch of people who were on the home straight themselves.

I raised my arms as I charged over the finish line. I had done it. From never having run 5 months earlier I had completed the London Marathon in just under 6 hours and 25 minutes.

I had a medal put around my neck, had some photos taken and then went off to find my family.

That was 4 days ago. I am still sore and my left knee still has a niggle but it was all worth it.

I am not planning to do another marathon. I think once in a lifetime is enough for me. But I am planning to keep up with the running, for now at least. I'll try and do 5 or 6 miles a couple of times a week. Because the crazy thing is I can do that now without even really thinking about it. And it would be a real shame to squander that rather extraordinary (for me at least) level of fitness.

It is an experience I will never forget.

Thanks again to all who sponsored and encouraged me to do this. My wife and I have been overwhelmed with the generosity of everyone who has given money to COSMIC in memory of our beautiful son Olly. To have been able to raise money for a charity who looked after us all in our time of need when Olly was in St Mary's hospital has been an privilege and a great way to honour his memory.